Provide direct support of the 11th Marine Regiment in time of conflict. That support may come in the traditional fashion of artillery support to maneuver forces, or by providing batteries to serve as provisional rifle companies. They also have the secondary mission of conducting civil-military operations or "CAG Ops".

Marines with 2/11, send a round high into the air with the new M777 howitzer.

The battalion was activated September 5, 1918 at Montierchame, France as the 2d Battalion, 11th Regiment. They were relocated during July–August 1919 to Hampton Roads, Virginia. and were deactivated August 11, 1919.

2/11 was reactivated on May 9, 1927 at Marine Corps Base Quantico, Virginia as the 2d Battalion, 11th Regiment. Deployed during May 1927 to Chinandega, Nicaragua and assigned to the 2d Brigade. They participated in operations against dissidents in May–July 1927. They were redesignated July 1, 1927 as the 2d Separate Battalion, 11th Regiment and relocated to San Diego, California. The battalion was deactivated September 10, 1927. They were again reactivated on January 5, 1928 at San Diego, California as the 2d Battalion, 11th Regiment. The battalion deployed during January 1928 to Corinto, Nicaragua and assigned to the 2d Brigade. They were deactivated August 20, 1929 on board the USS Henderson while en route to the United States.

The battalion was reactivated on August 7, 1950 at Camp Pendleton as the 2nd Battalion, 11th Marines, 1st Marine Division and deployed during August–September 1950 to Kobe, Japan. They participated in the Korean War, operating at Inchon-Seoul, the Chosin Reservoir, East Central front, Western front. They were stationed at the Korean Demilitarized Zone from July 1953-March 1955 and finally relocated during March 1955 to Camp Pendleton, California.

Deployed during December 1990 with Regimental Landing Team 5, 5th Marine Expeditionary Brigade to Southwest Asia. They participated in the defense of Saudi Arabia until January 1991 and proceeded to participate in the liberation of Kuwait in January - May 1991 operating in Um Guar Al-Juba, Al Wafrah. Following the war they took part in the Bangladesh relief effort Operation Sea Angel in May 1991. The battalion returned on June 29, 1991 to Camp Pendleton, California, and was last the Gulf War combat unit to return stateside.

The flexibility of the MEU was demonstrated with the Iraq crisis in late 1998 regarding the regime not complying with the U.N. weapons inspections process. All four ARG ships had just completed Exercise Foal Eagle off the coast of Korea, and were heading to various port visits for liberty, when each ship received the call in early Nov 1998 to sail immediately to Okinawa to onload the 31st MEU.

A significant portion of the 31st MEU’s 2000 Marines were engaged in urban warfare training in Guam when their message to return to Okinawa came in November. The rest were still in Okinawa, but approximately a quarter of those were a new infantry battalion, just rotating in from California. The battalion had just two days to gather all their personnel to get ready to deploy.

The 31st MEU and ships’ company personnel started their initial onloads to the ships on 9 Nov and completed the morning of 11 Nov. In one night alone, they loaded more than 170 pallets of equipment, weapons, and cargo. In addition, a C-5 Galaxy from Marine Corps Air Station El Toro, originally scheduled to bring maintenance supplies and tools to Okinawa two weeks later, arrived early on 10 Nov 1998 in order to restock the MEU’s Air Combat Element. This evolution was a part of the normal supply rotation, but the shipment arrived a week early – just in time to load onto the ships before they departed.

From Nov 1998 to Feb 1999, the MEU participated in operations in the Persian Gulf and off the coast of Kuwait, including Operation Southern Watch and Operation Desert Fox.

In December 1998 2/4 participated as the Battalion Landing Team (BLT) for the 31 Marine Expeditionary Unit Special Operations Capable (MEUSOC). The operation, named "Desert Fox", was a retaliation to Saddam Hussein's refusal to comply with U.N. Security Council Resolutions that led to a coalition air bombing campaign. The Marines of 2/4 were also set up in a defense at and around Muttla ridge, in Kuwait, to act as a deterrent for any Iraqi attack on Kuwait that might have followed the air campaign.

2/11 deployed during January 2003 with the 1st Marine Division to Kuwait. They participated in the 2003 invasion of Iraq as part of Regimental Combat Team 5. The battalion relocated during back to Camp Pendleton, California in August 2003. In August 2004, the battalion again deployed in support of OIF and operated as a provisional military police with the 1st Marine Division in Ramadi, Iraq. They returned to Camp Pendleton in March 2005. From then to September 2007, individual batteries continued to deploy as both traditional artillery and provisional military police throughout Al Anbar.

From February 2008 through February 2009 the battalion deployed as civil affairs unit to areas of Fallujah, Ramadi and far western Al Anbar Province.